History of the present illness

This is an 11-year-old white female who was referred by her orthodontist for evaluation of a “cyst” associated with impacted tooth #22 (Figure 1). She was asymptomatic and was not aware of the lesion. Clinical examination revealed an expansion of facial cortex below teeth #s 21-25 with missing tooth #22 and retention of deciduous tooth # M.  No other clinical or neurological abnormalities were detected. The initial panoramic and lateral cephalic radiographs revealed a unilocular radiolucent lesion around the crown of a horizontally impacted #22 (Figure 1).